Answer:
255 m
Step-by-step explanation:
From the given question, the surface of the water body is the reference point. And this point is assumed to be 0, so that any distance above it is positive, and any distance below is negative. This is synonymous to the number line system.
Thus,
For the aircraft, its height = +200 m
For the submarine, its depth = -55 m
So that the difference between the submarine and aircraft can be determined as;
200 - (-55)
= 200 + 55
= 255 m
The distance between the submarine and aircraft is 255 m.
Answer:
R (t) = 60 - 60 cos (6t)
Step-by-step explanation:
Given that:
R(t) = acos (bt) + d
at t= 0
R(0) = 0
0 = acos (0) + d
a + d = 0 ----- (1)
After
seconds it reaches a height of 60 cm from the ground.
i.e


Recall from the question that:
At t = 0, R(0) = 0 which is the minimum
as such it is only when a is negative can acos (bt ) + d can get to minimum at t= 0
Similarly; 60 × 2 = maximum
R'(t) = -ab sin (bt) =0
bt = k π
here;
k is the integer
making t the subject of the formula, we have:

replacing the derived equation of k into R(t) = acos (bt) + d

Since we known a < 0 (negative)
then d-a will be maximum
d-a = 60 × 2
d-a = 120 ----- (3)
Relating to equation (1) and (3)
a = -60 and d = 60
∴ R(t) = 60 - 60 cos (bt)
Similarly;
For 

where ;

Then b = 6
∴
R (t) = 60 - 60 cos (6t)
Answer:
1/3
Step-by-step explanation:
since the total number of marbles are 3+7+5=15
and the number of green marbles=5
so probability of three marbles drawn being green=5/15=1/3